• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Photosynthesis is the process in which light energy, trapped by chlorophyll, is used to convert carbon dioxide and water into glucose and oxygen.

Extracts from this document...

Introduction

Plan Introduction All living organisms need food. Animals take in 'ready-made' food which they digest. They use the digested products for energy and to build new cells and tissues. Plants also require raw materials for building tissues and a source of energy. They manufacture everything they need out of simple ions and compounds available in the environment. The building up of complex molecules from simpler substances requires energy and enzymes. The enzymes are in the plants cells and the energy comes from sunlight. The process is called photosynthesis. Plants are able to absorb and use light energy because they have a green pigment, chlorophyll, contained in chloroplasts in some of their cells. Chlorophyll allows the energy in sunlight to drive chemical reactions. Chloroplasts act as energy transducers, converting light energy into chemical energy. Photosynthesis is the process in which light energy, trapped by chlorophyll, is used to convert carbon dioxide and water into glucose and oxygen. Carbon Dioxide + Water Glucose + Oxygen 6CO2 + H2O C6H12O6 + 6O2 There are four main things which affect the rate of photosynthesis: * Light intensity * Carbon dioxide * Water * Temperature for enzyme activity These are called limiting factors. Whichever one of these is furthest away from its optimum level most affects the rate of the overall process. ...read more.

Middle

Therefore the closer the light bulb is to the pondweed; the more bubbles should be produced from the stem. I think this because as the light bulb moves towards the pondweed, the light intensity increases, and therefore so should the rate of photosynthesis. This is why plants photosynthesize during the day and not during the night. Before planning this investigation, we completed a trial experiment. The purpose of this was to give us an idea of the experiment we were going to do. This meant that we could avoid making mistakes mid-investigation, and also finding results which do not accurately represent what should occur. Obtaining Evidence To make the experiment as accurate possible I made sure all measurements were the same and made sure that the constants did not vary. If for any reason something didn't go to plan, that particular experiment was repeated and not recorded. No sunlight came in, and the only light that was in the room was that of the lamps. After each experiment the boiling tube was emptied of water and sodium bicarbonate and refilled, making sure that every time the boiling tube contained the same quantities. I also left the fresh water a couple of minutes before adding the sodium bicarbonate, so the pondweed could get used to the water around it. ...read more.

Conclusion

This may have meant that the number of bubbles I counted was inaccurate. The only anomalous results we received were at the very beginning of the investigation. At first no bubbles were produced, so we changed for a different piece of pondweed. Fortunately the 2nd piece of pondweed worked well. The anomalous results were not included in the results table. If I did the experiment again to get better results, I would find a wider range of results and repeat each experiment three times. I would also move the pondweed by 2.5cm rather than 5cm. I couldn't do this originally because there wasn't enough time. My results allow me to reach a conclusion. If I were asked to make a prediction of how many bubbles would be released with a distance between the light source and weed of 12.5cm I could use my trend line and make an accurate prediction. To get more evidence to support my theory I would change the variable. I would perhaps alter the amount of sodium bicarbonate, but keep the light intensity constant. This would give me a broader idea on what factors affect the rate of photosynthesis. If I did extend the enquiry I think I would find that the rate of photosynthesis could be changed by a number of factors, each partly in control of the overall process. Ben Sims 10H Biology Coursework ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Green Plants as Organisms essays

  1. Marked by a teacher

    An investigation into the abundance of fresh water black fly larvae, Simuliidae, between pools ...

    4 star(s)

    1 Brightly coloured tray - This is where the organisms are transferred from the net. The organisms can be clearly identified against the bright background, this will lower the chance of miss identification thus improving the accuracy of the results 4.

  2. What is the effect on the rate of respiration of yeast cells with glucose ...

    corresponds to a small uncertainty, or error within the results making them more accurate and reliable. The rates of reaction were calculated from each graph drawn using the results from the actual experiment. Drawing a tangent to the curve at any point where the curve was smoothly drawn did this.

  1. An Investigation into Species Diversity with distance along a Pingo.

    Thus the time for evaporation to occur will be the same for each soil sample. * Similarly take out all petri dishes after 12 hours as opposed to taking them out individually and calculating the percentage water, as this will again ensure that each sample has the same amount of time to dry out.

  2. How temperature affects the rate of photosynthesis.

    As temperature will be increased, all the molecules of the dark stage will gain more kinetic energy and the probability of them colliding and forming or breaking bonds will increase. Therefore more products will be formed and the rate of the reactions will increase.

  1. Investigation into the relationship between the density of fresh water shrimps in fleet brook ...

    The digital meter gives the pH to a far greater degree of accuracy. There is no comparison with colour charts needed. Care should be taken to ensure that the pH meter is properly calibrated before use. To measure dissolved oxygen concentrations of water.

  2. Photosynthesis.In photosynthesis the raw materials are carbon dioxide and water. They react to form ...

    In photosynthesis the raw materials are carbon dioxide and water. They react to form the products of the reaction-oxygen and starch (glucose that has been stored). The reactions need energy and this comes from light. The green chloroplasts allow light to be used as energy and therefore both of these things are like helpers in the reaction.

  1. Consumer Marketing Plan.

    Sports drinks are more expensive than water on a per bottle basis. A 950 ml bottle of Gatorade is sold for $2.49. Powerade is comparable in price to Gatorade. Distribution Water is sold by the bottle through convenience stores or through vending machines placed in office lunchrooms, malls, or universities.

  2. Absorption Spectrum of Chlorophyll.

    All green plants contain chlorophyll a and chlorophyll b in their chloroplasts. Chlorophyll b differs from chlorophyll a by having an aldehyde (-CHO) group in place of a methyl group (-CH3) (Gross, 1991). This aldehyde group is also the reason that chlorophyll b has a greater molecular weight than chlorophyll a.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work